Device for the production of false twisted yarns

ABSTRACT

A device for the production of false twisted yarns which includes a first plate having a passage for the yarn therethrough; a second plate having a passage for the yarn therethrough aligned with the passage of the first plate and a surface in abutting relation to a surface of the first plate; and at least one curved conduit defined by recesses in at least one of the abutting surfaces of the first and second plates, such conduit communicating with the passages through the first and second plates. Means is provided to hold the yarn in a substantially constant position when traveling through the passages of the first and second plates and the curved conduit converges substantially tangentially toward such means to hold the yarn in place. When a rapidly moving fluid, e.g., air, is passed through the curved conduit, the same impinges upon the yarn and a false twisting effect occurs.

[HI 3,811,260 May 21, 1974 DEVICE FOR THE PRODUCTION OF FALSE- TWISTED YARNS [75] lnventor: Gabriel Ohayon, Lyons, France [73] Assignee: Rhone-Poulenc Textile, Paris,

France 22 Filed: Dec. 7, 1971 21 Appl.No.:205,553

Related US. Application Data [63] Continuation-impart of Ser. No. l52,733, June 14,

197l, Pat. N0. 3,724,040.

[52] US. Cl 57/77.3, 28/l.4, 57/34 HS,

57/157 F, 57/157 TS [51] Int. Cl D02g 1/04 [58] Field of Search, .t. 57134 HS, 34 B, 157 F, I 57/157 TS, 77.3, 77.33; 28/14, 72.12

Primary Examiner.lohn Petrakes Attorney, Agent, or Firm- Sherman & Shalloway [5 7] ABSTRACT A device for the production of false twisted yarns which includes a first plate having a passage for the yarn therethrough; a second plate having a passage for the yarn therethrough aligned with the passage of the first plate and a surface in abutting relation to a surface of the first plate; and at leastone curved conduit defined by recesses in at least one of the abutting surfaces of the first and second plates, such conduit communicating with the passages through the first'an'd second plates. Means is provided to hold the yarn in a substantially constant position when traveling through the passages of the first and second plates and, the curved conduit converges substantially tangentially toward such means to hold the yarn in place.- When a rapidly moving fluid, e.g., air, is passed through. the curved conduit, the same impinges 111905 the yarn and a false twisting effect occurs.

11 Claims, 11 Drawing Figures PmNTEnmel m4 F/a f0 DEVICE FOR THE PRODUCTION OF FALSE TWISTED YARNS This application is a continuation-in-part application of application Ser. No. 152,733, filed June 14, 1971, now US. Pat. 3,724,040.

BACKGROUND OF THE INVENTION It has been known for a long time and various processes have been proposed to obtain yarns crimped by false twisting by utilizing pneumatic means. For example, French Pat. No. 791,906 disclosed a process by which artificial thermoplastic yarns were subjected to the action of a gaseous fluid moving with a rolling motion, the device described being one which, while effective at low texturing speeds, does not allow the utilization of high texturing speeds so necessary in modern production and manufacturing techniques.

In addition to, the device set forth in French Pat. No. 791,906, since the development of such device, various devices have been proposed for texturing thermoplastic synthetic or artificial yarns by means of a rapidly moving fluid. Generally, such devices comprise a substantially cylindrical duct which acts as a texturing chamber through which the yarn passes with another duct delivering the fluid to the texturing chamber. While such devices of the prior art have the advantage of being simple in form, the known devices for producing false twisted yarns by means of a rapidly moving fluid impinging the yarn have problems with regard to manufacturing since such devices generally require the perforating ofcylindrical cavities inside of a block, this being difficult to provide with perfect reproducibility and in a manner which is economically feasible to the textile industry.

Moreover. prior art processes utilizing such conventional devices are characterizedby the fact that the rapidly moving fluid surrounds and impinges the yarn tangentially, pulling the yarn in the direction of its rotation toward the center ofa whirlpool. Accordingly, the yarn is subjected to radial constraints, the yarn oscillates due to the turbulence created, and under such conditions, it is extremely difficult, if not impossible, to obtain a yarn having regular characteristics.

SUMMARY OF THE INVENTION The foregoing disadvantages of previous processes and devices for carrying out such processes have been overcome in accordance with the present invention providing a device for the production of false twisted yarns, wherein the device comprises two plates defining a passage therethrough for travel of the yarn and at least one curved conduit defined by recesses in the abutting surfaces of the plates, the curved conduit being substantially perpendicular to and communicating with the passages through which the yarn travels, the curved conduit converging substantially tangentially toward the yarn. Such'device is particularly characterized in that the same includes an obstacle or means for maintaining the yarn in position during impingement by the rapidly moving fluid, such means or obstacle being located at the rear of the yarn with respect to the point of impact of the fluid upon the yarn. In this way. when a rapidly moving fluid is passed through the curved conduit, the same impinges the yarn in a substantially tangential manner so as to false twist the same through the impingement of the rapidly moving fluid upon the moving yarn, the yarn being held in place by a suitable means and located at the rear of the yarn with respect to point of impact of the fluid.

In accordance with a first embodiment of the'present invention, the device for the production of false twisted yarns comprises two plates having recesses in abutting surfaces defining a circular conduit disposed in the same plane and substantially perpendicular to the passage for the travel of the yarn, the means for holding the yarn in place constituting a solid piece serving to position and hold the yarn. The curved conduit for passage of the rapidly moving fluid may be formed in one of the two plates with the other plate being substantially solid or may be formed in both plates wherein the recesses in the abutting surfaces together form the necessary curved conduit. Additionally, a pneumatic means for holding the yarn in position is applicable.

Accordingly, it is a principal object of the present invention to provide a process and device for carrying out such process for the production of false twisted yarns, wherein such process and device eliminate the inherent deficiencies and disadvantages of prior art proposals.

It is a further object ofthe present invention to provide such a device for the production of false twisted yarns, wherein the device includes at least two plates having abutting surfaces, the fluid impinging upon the yarn passing through atleast one curved conduit defined by recesses in such abutting surfaces and allowing the substantially tangential impingement of the fluid upon the moving yarn, the device being characterized by an obstacle or means which maintains the yarn in position during impingement by the fluid, such obstacle or means being located at'the rear of the yarn with respect to the point of impact of the fluid upon the yarn.

subbstantially constant position as the yarn travels through the passages in the plates comprises mechanical means or one or more auxiliar'y jets of fluid located at the rear of the yarn with respect to the point of impact of the fluid upon the yarn. I

Yet a further object of the present invention resides in a process for the production of false twisted yarns utilizing the above device and wherein at least one fluid jet impinges a yarn moving substantially perpendicular thereto from at least one curved conduit so arranged that the fluid jet impacts the yarn substantially tangentially, the yarn held in a substantially constant position.

Still further objects and advantages of the novel process and device of the present invention will become more apparent from the following more detailed de-' scription thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing objects of the present invention and the characteristic features thereof can be clearly seen in the drawings wherein:

FIG. 1 is a diagrammatic view illustrating a yarn drawing system utilizing the false twisting device of the present invention;

FIG. 2 is an exploded view in perspective of the false twisting device of the present invention;

FIG. 3 is an exploded view in perspective of a further embodiment of the false twisting device of the present invention;

FIG. 4 is a plan view of one plate of another embodiment of the false twisting device of the. present invention; 1

FIG 5 is a plan view of one plate of another embodiment of the false twisting device of the present invention;

FIG. 6 is a plan view of one plate of another embodiment of the false twisting device of the present invention;

FIG. 7 is a plan view of one plate of another embodiment of the false twisting device of the present invention;

FIG. 8 is a plan view of one plate of another embodiment of the false twisting device of the present invention;

DESCRIPTION OF THE PREFERRED I EMBODIMENTS FIG. I diagrammatically represents a drawing process, wherein a false twisting device, such as in accordance with the present invention, is utilized. As seen in FIG. I, a yarn I0 is wound off ofa spool or bobbin 12 by means of a setof delivery rollers 14 and 16 and 'a pressing roller 18. The yarn 10, after being wound off the bobbin or spool I2 by means of delivery rollers 14 and I6 and pressing roller 18, passes over a heating plate 20, and then through the false twisting or textur ing device 22 in accordance with the present invention.

Yarn 10, after passing through the false twisting or textur'ing device 22, passes over a set of take-up rollers 24 and 26 equipped with an untwist locking means 28 before it is wound up on cop 30 by means ofa device with a ring 32 and traveler 34.

A first embodiment of the false twisting device of the present invention is illustrated in FIG. 2. As seen in FIG. 2, false twisting device 22 consists of two blocks or plates, 40 and 42, in this case parallelepipedal blocks or plates. The first or upper plate 40 is held in abutting relation to the second or lower plate 42 by means of projections orstuds 44 and 45 which fit, respectively, into mating holes or apertures 46 and 47. As seen in FIG. 2, studs 44 and 45 project from the uppermost surface 48 of the second or lower plate 42, which surface 48 is in abutting relation to the lowermost surface 50 of the first plate or upper plate 40.

Associated with false twisting device 22 is a means for introducing a rapidly moving fluid, illustrated by inlet and delivery pipe 52. The rapidly moving fluid, preferably compressed air, is introduced through inlet A means 62 to hold the yarn in a substantially constant position when traveling through passages 58 and 60, in the form of a solid obstacle, is located at the rear of the yarn with respect to the impact of the fluid and, as seen in FIG. 2, is formed by a portion of the wall of slits or passages 58 and 60. This means 62 for holding the yarn in a substantially constant position prevents the yarn from moving rearwardly in the false twisting device when the rapidly moving fluid impinges the yarn in a substantially tangential manner from curved conduit 56. This, therefore, allows for a false twisting of the yarn in a manner eliminating the deficiencies of prior proposals. As seen in FIG. 2, a movable element 64 is provided to partially close passages 56 and 60' after threading the yarn therethrough. Such movable or adjustable element or part 64 prevents the yarn from being inadvertently pushed out of passages 56 and 60 through the action'of the rapidly moving fluid.

As seen in FIG. 2, stud 44 is positioned in curved conduit 56 in such a manner as to obstruct the same and to prevent any recycling of the rapidly moving fluid. In the embodiment shown. in FIG. 2, the supply of the rapidly moving fluid and curvedconduit S6 for impinging the rapidly moving fluid on the yarn to be false twisted in a substantially tangential manner are solely in one of the two plates or blocks, in this case in the bottom or second plate 42. However, as will-be shown by reference to'FIG'. 3, the curved conduit or groove may be present in both blocks or plates.

Such an embodiment is illustrated in FIG. 3. The embodiment of FIG. 3 differs from that of FIG. 2 only in that the curved conduit for passage of the rapidly moving fluid and inlet therefor are not located in one of the two plates, but rather are presently partially in both the upper or first plate 40 and bottom or second plate 42. For example, referring to FIG. 3, it is noted that the rapidly moving fluid is introduced through inlet 52' into feeding duct or channel 54' whichends in curved conduit 56. All other features of the lower plate 42 in FIG. 3 are identical with those in FIG. 2.

Additionally, the top or first plate 42 contains a feeding duct or channel 54" which again ends in curved conduit 56". It is quite obvious by reference to FIG. 3 that a suitable embodiment falling thereunder would include the presence of the conduits in both the top and bottom plates wherein the depths of the recesses were substantially equal, i.e., the conduits for passage of the rapidly moving fluid are formed by the equally dimensioned recesses in the top and bottom plates. It should be additionally quite clear, however, that any embodiment between that of FIG. 3 and that of FIG. 2 can be utilized and thedepth of the recesses in the top and seen in FIGS. 2 and 3. In this regard, according to the process of the present invention, rapidly moving fluid impacts the yarn in a substantially tangential manner, such that the direction of rotation of the yarn is opposite of the direction of rotation of the fluid. For example, if rotation of the fluid is positive, the twisting of the yarn is effected in a negative direction and vice versa.

In accordance with the process of the present invention, the rapidly moving fluid does not in any way damage the yarn since, by utilizing the device as shown, the yarn is not subjectedto extremely violent turbulence. Accordingly, the yarn which is obtained by carrying out the process of the present invention, utilizing the device of the present invention, is one which is more regular than that which can be obtained with conventional false twisting means.

As seen in FIGS. 2 and 3, the obstacle against which the yarn rests and which positions the yarn during impingement by the rapidly moving fluid may be a mechanical means such as a portion of the wall of the passage through which the yarn travels. Alternatively, however, the obstacle against which the yarn rests and which positions the yarn may be any suitable mechanical means such as an inserted metal or plastic part, etc. Additionally, as will be readily apparent from a consideration of the description of the remaining drawings which follows, 'such obstacle against which the yarn rests may be a pneumatic means such as one or more auxiliary jets arriving substantially at the tangential point of the curved duct and the passage through which the yarn travels. I

It is additionally noted that, while FIGS. 2 and 3 have not been described with regard to specific dimensions and forms, it should be recognized that the dimensions of the cross-section of the curved conduit or groove can be easily determined and varied based on the degree of twist desired, since the fluid consumption is dependent on the loss of pressure in such curved conduit. Preferably, the conduit has a simple geometric form as indicated previously, i.e., circular or other form, which can be easily manufactured and reproduced. This, therefore, allows for the greater reproducibility of the process and device of the present invention and the more regular characteristics of the false twisted yarn which is produced.

The device of FIGS. 2 and 3 is one in which the yarn is given an S-twist due to the relationship of the curved conduit and yarn. It is quite obvious that a similar device can be made which will impart a Z-twist to the yarn while utilizing a curved conduit which is symmetrical to that which imparts the S-twist with respect to the median longitudinal plane of the passage through which the yarn travels. This is seen by reference to FIG. 4.

The device illustrated in FIG. 4 is similar to that shown in FIG. 2, onlythe bottom or lower plate being shown in plan view. The device of FIG. 4, however, differs from that of FIG. 2 in that a Z-twist is imparted to the yarn which is false twisted, rather than the S-twist of FIG. 2. For example, in FIG. 4, the false twisting device includes a feeding duct or channel 66 ending in a curved conduit 68, the obstacle or means 62 to hold the yarn in position being formed by a portion of the wall of curved conduit 68. The feeding duct or channel 66 and curved conduit 68 of FIG. 4 are symmetrical with the feeding duct or channel 54 and curved conduit 56 of FIG. 2 and constitute a mirror image of the same, the symmetry being with respect to the median longitudinal plane of the passage 60 through which the yarn travels. All other elements of FIG. 4 are the same as those of FIG. 2 and are accordingly numbered. It should be noted, however, by reference to FIG. 4 that, in this embodiment, the stud is positioned in curved conduit 68, obstructing the same and preventing any recycling of the rapidly moving fluid.

The device illustrated in FIG. 5 is a still further modification of the bottom plate of FIG. 2. In this device, means 62 for holding the yarn in a substantially constant position has been eliminated and the yarn is held in position by means of an auxiliary jet of fluid impinging the yarn from conduit 70. Accordingly, the device of FIG. 5 is one in which a mechanical means for holding the yarn in a substantially constant position has been replaced with a pneumatic means, i.e., a jet of rapidly moving fluid emanating from conduit 70.

The device of FIG. 6 is a still further modification of that of FIG. 2. In this regard, it will be noted that, in the device of FIG. 6, all elements are the same as that of FIG. 2, except that FIG. 6 includes a further oblique duct or conduit 72 through which an auxiliary jet of fluid passes. In this regard, such oblique duct or conduit 72 does not replace obstacle 62, but is in addition to the same in accordance with the embodiment of FIG. 6.

The device illustrated in FIG. 7 comprises a further embodiment of that shown in FIG. 2. In FIG. 7, stud 44 has been moved from curved conduit 56 and is located outside the conduit for passage of the rapidly moving fluid. Since conduit 56 is not in any way obstructed, the rapidly moving fluid entering the same divides into two opposed jets. The two opposed jets of the curved conduit will impinge the yarn tangentially and together have the effect of maintaining a substantially constant position of the yarn.

Referring to FIG. 8, it is noted that a further embodiment of the device of FIG. 2 is shown. The device of FIG. 8 is similar to that of FIG. 2, except that, in addition to curved conduit 56, the false twisting device includes a radial conduit 74. As seen in FIG. 8, the radial conduit 74 passes a portion of the rapidly moving fluid in curved conduit 56 in a straight line toward the yarn in a manner so as to impinge the same in a nontangential manner. The precise positioning, coonfi guration and cross-sectional size of radial conduit 74 depends upon the effect which is desired and can be easily chosen for any particular purpose. Additionally, two or more such radial conduits can be utilized with advantage for particular purposes.

FIG. 9 shows a still further embodiment of the false twisting device of FIG. 2, FIG. 9 being one in which the circular curved conduit 56 has been replaced by a conduit 78 in the form of a loop. All other features of FIG. 9 are the same as FIG. 2. In this regard, while FIGS. 2 through 8 have been set forth to illustrate the preferred employment of a circular conduit to impinge the yarn tangentially with the rapidly moving fluid, it should be clear from a consideration of FIG. 9 that the conduit need not be circular in form, but rather any curved shape can be utilized.

FIGS. 2 through 9 have been described in connection .with the employment of a single curved conduit which,

by passing a rapidly moving fluid to impinge the yarn in a substantially tangential manner, provides for a false and 45 are, respectively, located in curved conduits 56 Y and 68 and obstruct the same, preventing any recycling of the rapidly moving fluid. In addition, it can be seen from FIG. 10 that the rapidly moving fluid in curvedconduits 56 and 68 impinges the yarn in a tangential manner, the yarn being positioned against obstacle 62.

It should be readily apparent from a review of FIG. 10 that, if the rapidly moving fluid is passed in equal amounts through curved conduits 56 and 68 simultaneously, no false twist will be imparted to the yarn, but I rather an interlacing will take effect such as shown in co-pending application Ser. No. 152,733, filed June 14, 197 l Accordingly, to provide the necessary false twisting in accordance with the present invention, means is provided to pass through rapidly moving fluid only through one of conduits 56 and 68 at a time, providing an..alternating flow of the rapidly moving fluid. In this way, it is possible to produce a yarn with an alternating twist. Such means for alter-nating'the flow of the rapidly moving fluid between conduits 56 and 68 is not shown, but can obviously comprise any known means for effecting the flow of the fluid.

.ltis, of course, also possible to operate the device of FIG. 10 in such a manner that the rapidly moving fluid is introduced through only one of the curved conduits 56 and 68. This allows the false twisting device to be utilized to provide either the S-twist or Z-twist, depending on the desired result, but only a single type of twist in connection with any particular yarn.

FIG. 11 shows a further modification of the device of FIG. 10. In FIG. 11, curved conduits 56 and 68 are staggered, although in the same plane. Accordingly, as seen in FIG. 11, his unnecessary that the curved conduits of the false-twisting device be precisely aligned with each other when two conduits are utilized.

Itshould be quite obvious that the falsetwisting device of the present invention can be prepared from any suitable material which is impervious to the: rapidly moving fluid, i.e., air. For example, the false twisting device is advantageously formed of metal or plastic by casting, molding or otherwise forming the two blocks of the false twisting device.

If should additionally be quite apparent that the size and configuration of the parts of the false twisting device can be varied where desired for paarticular purposes. It is important, however, that the cross-section of curved conduit or conduits be smaller in relation to the feeding duct or channel and inlet pipe so as to accelerate the fluid and impinge the same upon the yarn at the highest possible speed.

In accordance with the process of the present invention, the rapidly moving fluid is passed through the curved conduit or conduits to impinge the yarn in a substantially tangential manner so as to work against the same and false twist the yarn. As indicated previously, it is preferable in accordance with the present invention that the planeof the rapidly moving fluid be plates or substantially perpendicular to the travel of the yarn. By impinging the fluid against the yarn in a substantially tangential manner, an efficient false twisting is achieved in a manner eliminating the difficulties and disadvantages of previous processes. The process and device of the present invention will now be illustrated by reference to the following example which is presented for purposes of illustration only and is in no way to be deemed as limiting the present invention.

EXAMPLE A device similar to that illustrated in FIG. 2 is used to texture a yarn in continuous manner, the characteristics of the device being as follows:

dimensions of plates and 42:

length 40 mm width 40 mm height 8 mm width of slit constituting yarn passages 58 and 60: 0.6

The foregoing example illustrates the applicability and advantageous utilization of the device of the present invention in the false twisting of yarns. In this respect, it should be obvious from the foregoing description that any. conventionally drawn and false twisted yarn, i.e., natural or synthetic yarn, can be false twisted in accordance with the present invention to produce an S-twist, Z-twist, or alternating S- and Z-twist, by allowing a fluid, i.e., compressed air, to attach and impinge the yarn in a substantially tangential manner whereby the direction of rotation of the yarn is opposite the di- I rection of rotation of the fluid. In this regard, the novel device and process of the preesent invention constitute a distinct improvement over conventional devices and processes for producing false twisted yarns.

While the present invention has been described primarily in connection with the foregoing exemplification and description, it should be understood that the present invention is in no way to be deemed limited thereto, but rather must be construed as broadly as all or any equivalents thereof.

What is claimed is:

l. A device for the production of a false twisted textured yarn produced by impinging a rapidly moving fluid upon a moving yarn including:

a. a first plate having a passage therethrough through which the yarn travels;

b. a second plate having a passage therethroug through which the yarn travels, said passage of said second plate being aligned with said passage of said first plate, said second plate having a surface in abutting relation with a surface of said first plate,

at least one of the abutting surfaces having a recess therein; c. means to hold said yarn in a substantially constant position when traveling through said passages of said first and second plates and the rapidly moving fluid impinges thereupon;

d. a curved conduit defined by said recess in said at least one of said abutting surfaces of said first and second plates, said conduit communicating with said passages through said first and second plates and converging substantially tangentially toward said means to hold yarn; and

e. means to supply a rapidly moving fluid to said curved conduit.

2. The device of claim 1 wherein said means to hold said yarn in a substantially constant position is a solid obstacle.

3. The device of claim 1 wherein said meansto hold said yarn in a substantially constant position is a pneumatic means adapted to supply a rapidly moving fluid in a direction substantially opposite that of said fluid impinging said yarn from said curved conduit.

4. The device of claim 3 wherein said pneumatic means is at least one auxiliary fluid jet.

5. The device of claim 1 wherein said curved conduit is defined by recesses in only one of said abutting surfaces-of said first and second plates.

6. The device of claim 1- wherein said curved conduit is defined by recesses in both of said abutting surfaces of said first and second plates.

7. The device of claim 1 wherein said first and second plates are held in abutting relation by means of projections from the abutting surface of one of said first and second plates and mating apertures in the abutting surface of the other of said first and second plates.

8. The device of claim 7 wherein said projections from the abutting surface of one of said first and second plates are located in said curved conduit so asto prevent free circulation of said rapidly moving fluid in said curved conduit.

9. The device of claim 1 further including means to partially close said passages of said first and second plates.

10. The device of claim 1 further including an additional curved conduit defined by an additional recess in said at least one of said abutting surfaces of said first and second plates and means to supply said rapidly moving fluid to one of said curved conduits.

11 The device of claim 10 wherein said means to supply said rapidly moving 'fluid supplies said rapidly moving fluid alternately to said curved conduits.

; UNITEDWSTATES PATENT; QFF W M CERTIFICATE OF LCORRECTION Patent No. 3,811,260 Dated May 21, 1974 1 Inventor(s) Gabriel Ohayon It is certified that error appears in the above-identified patent and that saidLetters Patent are hereby corrected as shown below:

.In the Heading, insert patentee's foreign application priority data as follows:

-- Claims priority, application France, No. 70/44885 Dec. 10, 1970 Signed and sealed this 26th day of November 1974 (SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Arresting Officer Commissioner" of Patent;

USCOMM-DC 60376-F'69 Q U.S, QOVERNMENY PRINTING OFFICE: 1969 0-366-334 FORM PO-1050 (10-69) 

1. A device for the production of a false twisted textured yarn produced by impinging a rapidly moving fluid upon a moving yarn including: a. a first plate having a passage therethrough through which the yarn travels; b. a second plate having a passage therethrough through which the yarn travels, said passage of said second plate being aligned with said passage of said first plate, said second plate having a surface in abutting relation with a surface of said First plate, at least one of the abutting surfaces having a recess therein; c. means to hold said yarn in a substantially constant position when traveling through said passages of said first and second plates and the rapidly moving fluid impinges thereupon; d. a curved conduit defined by said recess in said at least one of said abutting surfaces of said first and second plates, said conduit communicating with said passages through said first and second plates and converging substantially tangentially toward said means to hold yarn; and e. means to supply a rapidly moving fluid to said curved conduit.
 2. The device of claim 1 wherein said means to hold said yarn in a substantially constant position is a solid obstacle.
 3. The device of claim 1 wherein said means to hold said yarn in a substantially constant position is a pneumatic means adapted to supply a rapidly moving fluid in a direction substantially opposite that of said fluid impinging said yarn from said curved conduit.
 4. The device of claim 3 wherein said pneumatic means is at least one auxiliary fluid jet.
 5. The device of claim 1 wherein said curved conduit is defined by recesses in only one of said abutting surfaces of said first and second plates.
 6. The device of claim 1 wherein said curved conduit is defined by recesses in both of said abutting surfaces of said first and second plates.
 7. The device of claim 1 wherein said first and second plates are held in abutting relation by means of projections from the abutting surface of one of said first and second plates and mating apertures in the abutting surface of the other of said first and second plates.
 8. The device of claim 7 wherein said projections from the abutting surface of one of said first and second plates are located in said curved conduit so as to prevent free circulation of said rapidly moving fluid in said curved conduit.
 9. The device of claim 1 further including means to partially close said passages of said first and second plates.
 10. The device of claim 1 further including an additional curved conduit defined by an additional recess in said at least one of said abutting surfaces of said first and second plates and means to supply said rapidly moving fluid to one of said curved conduits.
 11. The device of claim 10 wherein said means to supply said rapidly moving fluid supplies said rapidly moving fluid alternately to said curved conduits. 